Early experience plays a critical role in shaping adult behavior. Epigenetic mechanisms of gene regulation have recently been implicated in mediating a cellular memory of early experience in the nervous system. In work funded by the parent grant, we are defining the mechanisms that lead to the generation of diversity in the sensory nervous system of C. elegans. In this competitive supplement, we propose to extend the scope of the parent grant to explore how early experience modifies adult sensory neuronal functions in C. elegans. Our preliminary data indicate that histone modification profiles are altered in response to early environmental experience. We will correlate the observed gene expression changes in animals with defined early experiences with their histone modification profiles (Aim 1), identify molecules that mediate these epigenetic changes (Aim 2), and investigate the consequences of the altered gene expression patterns on adult behavior. [unreadable] PUBLIC HEALTH RELEVANCE: Epigenetic mechanisms are increasingly being implicated in the regulation of gene expression. Aberrant epigenetic regulatory pathways are now known to be involved in a large number of disorders including cancer, drug addiction, autism and additional cognitive disorders. The proposed work in the C. elegans nervous system will allow us to identify new molecules and pathways by which epigenetic mechanisms translate early experiences into altered patterns of gene expression and neuronal function in adult animals. [unreadable] [unreadable] [unreadable]